1. Field of the Invention
The present invention relates to a modular arrangement for the mounting of a variety of valve and choke actuators on a series of valves and chokes having standard mountings for the actuators. In particular, a mounting arrangement common to the different actuators and to the different valves and chokes permits a very simple procedure for the replacement or interchange of the equipment items based upon this design.
2. Description of the Related Art
Equipment used in the oilfield is subject to very severe operating conditions, so that equipment failures are common. Given the high cost of downtime in the oilfield, it is necessary to be able to service or replace faulty equipment items. In the normal case, it is more practical to replace or interchange the equipment than to repair it on site. Additionally, because a very large amount of oilfield equipment is rented to the rig operators, rather than sold, it is necessary to be able to quickly interchange equipment item subassemblies in order to provide a rental item which is properly configured for the requirements of the rig operator.
Traditionally, equipment items such as valves and chokes and their actuators have been repaired in the field. These equipment items have not been easy to service, given that the valves or chokes and their actuators have been closely integrated, rather than modular in construction. As a consequence, replacing an actuator typically requires partially disassembling the attached valve or choke in order to separate the piece. Naturally, replacing the valve or choke on a good actuator has required the same involved level of disassembly and reassembly.
Efforts have been made to simplify the coupling of actuators and rotary valves such as described in U.S. Pat. Nos. 4,633,897; 5,203,370; 5,564,461; 6,062,539; and 6,450,477B1. However, these solutions have not provided an easily disassembled coupling for joining the output rod of a linear actuator with the shaft of a valve or choke.
A need exists for hardware that can be more easily serviced by simple, rapid interchanges of the problematic or undesired equipment item with a functional item of the desired type. Additionally, by providing equipment subassemblies with common interface designs, the manufacturers and rental agencies and other equipment owners can maintain smaller inventories, with attendant cost savings.